Former President Barack Obama will endorse Joseph R. Biden Jr. on Tuesday, continuing the unification of Democratic leaders around the party’s presumptive presidential nominee.
Mr. Obama’s endorsement of his former vice president, expected via video, comes just one day after Senator Bernie Sanders of Vermont, who had been Mr. Biden’s last challenger, also endorsed him.
While the Democratic race was competitive, Mr. Obama remained publicly neutral, even as multiple candidates tried to link themselves to him. But now, with the primary effectively over, attention is turning to the potentially difficult task of unifying the party for the general election — and Mr. Obama is uniquely positioned to help do that.
Behind the scenes, he has been involved for some time and played a key role in persuading Mr. Sanders to end his campaign and endorse Mr. Biden.
Katie Glueck contributed reporting.